Adjustable spacer

ABSTRACT

A medical targeting and device introduction system includes an introducer having a cannula, and a hub. The cannula is defined, at least in part, by an inner lumen. The hub includes a latch to releasably secure the hub to a biopsy device. The hub includes a proximal end and a distal end. The latch extends from the proximal end, and the hemostatic valve is interposed within the introducer.

RELATED APPLICATION DATA

The present application is a continuation of pending U.S. patentapplication Ser. No. 12/114,294, filed May 2, 2008, the priority ofwhich is claimed under 35 U.S.C. §120, and the contents of which isincorporated herein by reference in its entirety, as though set forth infull.

TECHNICAL FIELD

The present disclosure relates to the field of medical devices and moreparticularly to a medical system that permits introduction of, amongother things, minimally invasive surgical instruments and other medicaltreatments into a patient's body.

BACKGROUND

Medical procedures have advanced to stages where less invasive orminimally invasive surgeries, diagnostic procedures and exploratoryprocedures have become desired and demanded by patients, physicians, andvarious medical industry administrators. To meet these demands, improvedmedical devices and instrumentation have been developed, such as cannulaor micro-cannula, medical introducers, vacuum assisted biopsy apparatus,and other endoscopic related devices.

In the field of tissue biopsy, minimally invasive biopsy devices havebeen developed that require only a single insertion point into apatient's body to remove one or more tissue samples. One such biopsydevice incorporates a “tube-within-a-tube” design that includes an outerpiercing needle having a sharpened distal end and a lateral opening thatdefines a tissue receiving port. An inner cutting member is slidinglyreceived within the outer piercing needle, which serves to excise tissuethat has prolapsed into the tissue receiving port. A vacuum is used todraw the excised tissue into the tissue receiving port and aspirates theexcised tissue from the biopsy site once severed.

Exemplary “tube-within-a-tube” biopsy devices are disclosed in U.S. Pat.Nos. 6,638,235 and 6,744,824, which are owned by the assignee of thepresent invention. Among other features, the exemplary biopsy devicescan be used in conjunction with Magnetic Resonance Imaging (MRI). Thiscompatibility is due to the fact that many of the components of thebiopsy devices are made of materials that do not interfere withoperation of MRI apparatus or are otherwise compatible therewith. It isdesirable to perform biopsies in conjunction with MRI because it is anon-invasive visualization modality capable of defining the margins of atumor.

Some biopsy devices may incorporate an introducer having an introducercannula that may be placed over the biopsy needle extending from aboutthe biopsy location to a location outside the patient. This introducermay remain in place after a biopsy is taken to permit the biopsy needleto be removed and a marker deployment device to be inserted within theintroducer cannula in order to permit a marker to be positioned withinthe biopsy site. However, with differing sizes of outer cannula forbiopsy needles and marker deployment devices, undesirable amounts ofleakage between the outer cannula and the biopsy needle and/or markerdeployment device may exist.

Additionally, biopsy needles and introducers are available in differinglengths, which demands that marker deployment devices be capable ofsliding within the introducer a predetermined length for proper markerdeployment. While a removable annular spacer positioned between theintroducer hub and the marker deployment device may permit the markerdeployment device to be inserted to a predetermined depth, interposingthe marker deployment device within an annular spacer may increase therisk of contamination. Additionally, a spacer interposed between theintroducer hub and the marker deployment device may not secure theintroducer hub to the marker deployment device, thereby requiring a userto simultaneously deploy a marker while ensuring that the markerdeployment device is properly positioned axially with respect to thedesired marker deployment location.

While the exemplary MRI compatible biopsy devices have proven effectivein operation, in some procedures it may be desirable to temporarilylatch a biopsy device or marker deployment device to an introducer. Afavorable introducer may also reduce leakage through the introducercannula and provide for adjustability for the insertion depth of themarker deployment device.

SUMMARY

A medical targeting and device introduction system includes anintroducer having a cannula, a hemostatic valve and a hub. The cannulais defined, at least in part, by an inner lumen. The hub includes alatch to releasably secure the hub to a biopsy device. The hub includesa proximal end and a distal end. The latch extends from the proximalend, and the hemostatic valve is interposed within the introducer.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, illustrative embodiments are shown indetail. Although the drawings represent some embodiments, the drawingsare not necessarily to scale and certain features may be exaggerated,removed, or partially sectioned to better illustrate and explain thepresent invention. Further, the embodiments set forth herein are notintended to be exhaustive or otherwise limit or restrict the claims tothe precise forms and configurations shown in the drawings and disclosedin the following detailed description.

FIG. 1 is a partially sectioned side view of a medical system accordingto an embodiment, with section graphics omitted for clarity.

FIG. 2 is a partially sectioned side view of a portion of the medicalsystem of FIG. 1, with section graphics omitted for clarity.

FIG. 3 is a side view of a portion of a medical system according toanother embodiment.

FIG. 4 is a partially sectioned side view of the medical system of FIG.3.

FIG. 5 is a partially sectioned side view of the medical system of FIG.4.

FIG. 6 is a partially sectioned side view of a medical system accordingto a further embodiment

FIG. 7 is a perspective view of a portion of the medical system of FIG.6.

FIG. 8 is a side view of a portion of the medical system of FIG. 6.

FIG. 9 is a partially sectioned side view of a medical system of FIG. 6,illustrating additional components

FIG. 10 is a partially sectioned side view of a medical system accordingto a further embodiment.

FIG. 11 is a sectioned side view of the medical system of FIG. 10.

FIG. 12 is an exploded side view of the medical system of FIG. 10.

FIG. 13 is a sectioned exploded side view of the medical system of FIG.10.

FIG. 14 is a view of the medical system of FIG. 10 taken along line26-26 of FIG. 10, enlarged for clarity

DETAILED DESCRIPTION

Referring now to the drawings, the preferred illustrative embodiments ofthe present invention are shown in detail. Although the drawingsrepresent some preferred embodiments of the present invention, thedrawings are not necessarily to scale and certain features may beexaggerated to better illustrate and explain the present invention.Further, the embodiments set forth herein are not intended to beexhaustive or otherwise limit or restrict the invention to the preciseforms and configurations shown in the drawings and disclosed in thefollowing detailed description

FIG. 1 illustrates a medical system 20. The medical system 20 includes amedical device, or biopsy device 22 (illustrated partially) and anintroducer 24 generally defining an axis A-A. The biopsy device 22includes a cutting element 30 sized for introduction into a patient'sbody and extends from a hand piece 32. The cutting element 30 includesan outer cannula 36 defined by a first outer lumen 38 and a first innerlumen 40, and an inner cannula 44 sized to fit concentrically within thefirst inner lumen 40. A motor or other motion generating device (notshown) may be provided with the hand piece 32 to rotate and/or translateinner cannula 44 within outer cannula 36. Biopsy apparatus similar todevice 22 can be seen by way of example in U.S. Pat. Nos. 6,638,235 and6,744,824, which are owned by the assignee of the present invention andare incorporated herein by reference in their entirety.

In the embodiment illustrated, the outer cannula 36 of the biopsy device22 includes a tissue piercing tip 46, such as a trocar tip, tofacilitate penetration of the system 20 into a patient's tissue. Inaddition to a trocar tip, it will be appreciated that the outer cannula36 may include other devices for piercing the patient's tissue,including without limitation, devices that use a laser or radiofrequencies (RF) to pierce the tissue.

As best seen in FIG. 2, the introducer 24 includes an introducer hub 50,an introducer cannula 52, and a latch portion 56. As will be describedin detail, system 20 is particularly, but not necessarily, suited foruse in biopsy procedures that identify the target biopsy site usingMagnetic Resonance Imaging (MRI) or comparable medical imaging modality.The introducer 24 may be made of a MRI compatible, medical gradematerial, such as 316 stainless steel or Inconel.TM. 625.

The introducer cannula 52 includes a generally cylindrical body 58having a distal end 60, a proximal end 62, an introducer outer lumen 64,and an introducer inner lumen 66. The distal end 60 defines a distalintroducer opening 70. The hub 50 includes a generally annular hubportion 76, a hemostatic valve 80, and the latch portion 56. The annularhub portion 76 includes a hub outer surface 82, a hub inner surface 84,a hub distal end 86, and a hub proximal end 88. The hub inner surface 84includes a generally cylindrical introducer cannula mating surface 90and a generally cylindrical valve mating surface 92. The latch portion56 includes a release button 100 and a latch 102 extending generallyparallel to the axis A-A having a latch tab 104 extending generallyperpendicular to and toward the axis A-A.

As best seen in FIG. 1, the biopsy device 22 includes a device distalend 106 defined by a distal surface 108, and a latch portion, or latchopening, 110. The latch opening 110 includes a latch tab interferenceportion 112.

As best seen in a comparison of FIGS. 1 and 2, the hemostatic valve 80includes a body 120 that is a self-sealing membrane that will permit amedical device, such as the biopsy device 24 or a site marker deploymentdevice, to pass therethrough while sealing around the medical device andwill reseal with itself after the medical device is removed from thevalve 80.

A medical device, such as the biopsy device 22 partially interposedwithin the introducer 24, may include a vacuum source (not shown). Thevacuum source may aspirate the biopsy site where the biopsy device 22removes a tissue sample.

The length of the outer cannula 36, from the distal surface 108 to thepiercing tip 46 is identified by the reference character “M” in FIG. 1.The length of the introducer 24 from the distal end 60 to the hubproximal end 88 is identified by the reference character “I” in FIG. 1.

FIGS. 3-5 illustrate an alternative embodiment of the medical system 20as a medical system 220. The medical system 220 includes a medicaldevice, or biopsy device 222 (illustrated partially in FIGS. 3 and 5)and an introducer 224 generally defining an axis B-B. The biopsy device222 includes a cutting element 230 that extends from a hand piece 232.The cutting element 230 includes an outer cannula 236 defined by a firstouter lumen 238 and a first inner lumen 240, and an inner cannula 244sized to fit concentrically within the first inner lumen 240. A motor orother motion generating device may be provided with the hand piece 232to rotate and/or translate inner cannula 244 within outer cannula 236.

In the embodiment illustrated, the outer cannula 236 of the biopsydevice 222 includes a tissue piercing tip 246, such as a trocar tip, tofacilitate penetration of the system 220 into a patient's tissue. Inaddition to a trocar tip, it will be appreciated that the outer cannula236 may include other devices for piercing the patient's tissue,including without limitation, devices that use a laser or radiofrequencies (RF) to pierce the tissue.

As best seen in FIG. 4, the introducer 224 includes a hub 250, anintroducer cannula 252, and a latch portion 256. As will be described indetail, system 220 is particularly, but not necessarily, suited for usein biopsy procedures that identify the target biopsy site using MagneticResonance Imaging (MRI) or comparable medical imaging modality.

As best seen in FIG. 5, the introducer cannula 252 includes a generallycylindrical body 258 having a distal end 260, a proximal end 262, anintroducer outer lumen 264, and an introducer inner lumen 266. Thedistal end 260 defines a distal introducer opening 270. The hub 250includes a generally annular hub portion 276, a hemostatic valve 280,and the latch portion 256. The annular hub portion 276 includes a hubouter surface 282, a hub inner surface 284, a hub distal end 286, and ahub proximal end 288. The hub inner surface 284 includes a generallycylindrical introducer cannula mating surface 290 and a generallycylindrical valve mating surface 292. The latch portion 256 includes arelease button 300 and a latch 302 extending generally parallel to theaxis B-B having a latch tab 304 extending generally perpendicular to theaxis B-B.

As best seen in FIG. 3, the biopsy device 222 includes a device distalend 306 defined by a distal surface 308, a latch opening 310, and anouter cannula sheath 312. The latch opening 310 includes a latch tabinterference portion 316.

As best seen in a comparison of FIGS. 4 and 5, the hemostatic valve 280includes a body 320 having a slit 322 formed therein. The slit 322generally segregates the body 320 into a first flap 326 and a secondflap 328 interconnected at an outer periphery, or outer edge, 330 suchthat the slit 322 does not intersect the outer edge 330. The first flap326 is defined by a first flap opening surface 334, and the second flap328 is defined by a second flap opening surface 336. The first flapopening surface 334 and the second flap opening surface 336 are formedso as to flex inwardly until the first flap opening surface 334 and thesecond flap opening surface 336 bindingly contact (FIG. 4) and provide aseal for the introducer inner lumen 266. To provide this resilientflexing for a self-sealing effect, the valve 280 may be made of asilicone or other suitable material that will bias the first flap 326and the second flap 328 toward a closed position.

The first flap opening surface 334 and the second flap opening surface336 are in contact in the closed position of FIG. 4 and provide a sealfor the introducer inner lumen 266 when the valve 280 does not have amedical device interposed therein. In FIG. 5, the first flap openingsurface 334 and the second flap opening surface 336 contact the firstouter lumen 238 so as to form a seal therebetween and restrict fluidsfrom leaking therepast and through the introducer cannula 252. In theembodiment illustrated, the hemostatic valve 280 is not punctured witheach use, but is a valve having a defined opening.

FIGS. 6-9 illustrate an alternative embodiment of the medical system 20as a medical system 420. The medical system 420 includes a medicaldevice, or site marker deployment device 422 (illustrated partially inFIG. 9) and an introducer 424 generally defining an axis C-C.

As best seen in the embodiment of FIG. 9, the site marker deploymentdevice 422 includes a deployment handpiece 430, a deployment rod 432,and a deployment cannula 434 extending therefrom. The deployment cannula434 includes a generally cylindrical body 436 having a distal deploymentend 438 defined, at least in part, by a distal deployment opening 440, aproximal deployment end 442, a deployment inner lumen, or inner surface,444, and a deployment outer lumen, or outer surface, 446. In theembodiment illustrated, the deployment inner lumen 444 and thedeployment outer lumen 446 are generally cylindrical.

The deployment cannula 434 is illustrated in FIG. 9 with a site marker448 (illustrated in phantom) interposed therein. The site marker 448 maybe an MRI identifiable marker, such as a collagen plug, metal spring, orother medical treatment. The deployment rod 432 extends at leastpartially through the hand piece 430 and the deployment cannula 434 andis used to urge the site marker 448 through the distal deploymentopening 440 when the deployment device 422 is desirably positioned, asdiscussed in greater detail below.

As best seen in FIGS. 6-9, the introducer 424 includes a hub 450, anintroducer cannula 452, and a pair of latch portions 456. As will bedescribed in detail, system 420 is particularly, but not necessarily,suited for use in biopsy procedures that identify the target biopsy siteusing Magnetic Resonance Imaging (MRI) or comparable medical imagingmodality.

As best seen in FIG. 8, the introducer cannula 452 includes a generallycylindrical body 458 having a distal end 460, a proximal end 462, anintroducer outer lumen 464, and an introducer inner lumen 466. Thedistal end 460 defines a distal introducer opening 470. The hub 450includes a generally annular hub portion 476, a first portion, orcollar, 478, a hemostatic valve 480, and the latch portions 456. Theannular hub portion 476 includes a hub outer surface 482, a hub innersurface 484, a hub distal end 486, and a hub proximal end 488. The hubinner surface 484 includes a generally cylindrical introducer cannulamating surface 490 (FIG. 9) and a generally cylindrical valve matingsurface 492 (FIG. 9). The collar 478 includes a generally cylindricalouter surface 494 and a generally annular collar end surface 496. Thehub proximal end 488 includes a generally cylindrical hub flange 498.Each latch portion 456 includes a release button 500 and a latch 502extending generally parallel to the axis C-C having a latch tab 504extending generally perpendicular to the axis C-C.

As best seen in FIG. 9, the deployment handpiece 430 of the site markerdeployment device 422 includes a deployment distal end 506 defined by adeployment distal surface 508. The deployment distal end 506 has a pairof latch openings 510 and a collar opening 512 formed therein. Eachlatch opening 510 includes a latch tab interference portion 514. Thecollar 478 is received within the collar opening 512. The hemostaticvalve 480 may be a valve 80 or a valve 280, as desired.

FIG. 6 illustrates the introducer 424 with a medical device, or a biopsydevice 528 interposed therein. The biopsy device 528 includes a cuttingelement 530 sized for introduction into the patient's body. The cuttingelement 530 extends from a handpiece 532. The cutting element 530includes an outer cannula 536 defined by a first outer lumen 538 and afirst inner lumen 540, and an inner cannula 544 sized to fitconcentrically within the first inner lumen 540. A motor or other motiongenerating device may be provided with the hand piece 532 to rotateand/or translate inner cannula 544 within outer cannula 536

In the embodiment illustrated, the outer cannula 536 of the biopsydevice 528 includes a tissue piercing tip 546, such as a trocar tip, tofacilitate penetration of the system 520 into a patient's tissue. Inaddition to a trocar tip, it will be appreciated that the outer cannula536 may include other devices for piercing the patient's tissue,including without limitation, devices that use a laser or radiofrequencies (RF) to pierce the tissue.

The handpiece 532 includes a biopsy device distal end 550 having abiopsy device distal surface 552 for abutting the collar 478 to restrictthe movement of the introducer 424 relative to the biopsy device 528.When the biopsy device 528 and the introducer 424 are coupled such asshown in FIG. 6, the length of the biopsy device 528, from the collarend surface 496 to the piercing tip 546 is identified by the referencecharacter “A2” in FIG. 6.

The length of the introducer 424 from the distal end 460 to the collarend surface 496 is identified by the reference character “B2” in FIGS. 6and 9. When the deployment device 422 and the introducer 424 are coupledsuch as shown in FIG. 9, the length of the deployment device 422, fromthe collar end surface 496 to the distal deployment opening 440 isidentified by the reference character “C2” in FIG. 9. The length of theintroducer 424 from the distal end 460 to the hub proximal end 488 isidentified by the reference character “D” in FIG. 9. When the deploymentdevice 422 and the introducer 424 are coupled such as shown in FIG. 9,the length of the deployment device 422, from the hub proximal end 488to the distal deployment opening 440 is identified by the referencecharacter “E” in FIG. 9.

In operation, a biopsy device, such as the biopsy device 528 is coupledwith the introducer 424 such that the outer cannula 536 is interposedwithin the introducer cannula 452 with the piercing tip 546 extendingfrom the distal introducer opening 470, as generally shown in FIG. 6.The biopsy device 528 is inserted into the introducer 424 until thecollar end surface 496 contacts the biopsy device distal surface 552. Inthis biopsy configuration, the system 420 may be inserted into apatient's tissue to remove a tissue sample from a biopsy site. Also inthis biopsy configuration, the valve 480 seals the introducer cannulasuch that fluids are restricted from flowing from the distal end 460 tothe proximal end 462.

Next, the system 420 is inserted into a patient's tissue to a desireddepth. This desired depth may be determined by viewing the system with aMRI during insertion. With the cutting element 530 positioned asdesired, a tissue sample is drawn into the outer cannula 536 andseparated from the surrounding tissue to form a biopsy site. A vacuumdrawn through the outer cannula 536 may be applied to facilitate acomplete separation and collection of the tissue sample.

Next, the biopsy device 528 is removed from the tissue as the introducer424 is maintained in a relatively stable position relative to and withinthe tissue. As the piercing tip 546 passes the valve 480, the valve 480seals with itself to restrict a loss of fluids from the biopsy site. Inthe embodiment described, the valve 480 is a valve 280 where the firstflap opening surface 334 and the second flap opening surface 336 flexinwardly until the first flap opening surface 334 and the second flapopening surface 336 bindingly contact (FIG. 4) and provide a seal forthe introducer inner lumen 466.

Next, the deployment device 422, with a site marker 448 interposedtherein, may be inserted into the introducer 424 (FIG. 9). Thedeployment device 422 is inserted into the introducer 424 until thedeployment distal surface 508 contacts the hub proximal end 488. Thedeployment cannula 434 is sized to fit within the introducer cannula452, but need not be snugly fit, since the valve 280 will reduce leakagetherebetween.

The site marker 448 may then be deployed by urging the site marker outof the introducer 424 through the distal introducer opening 470.Deployment devices for deploying a site marker may be found in U.S. Pat.No. 7,044,957.

The deployment device 422 and the introducer 424 may be removedsimultaneously by urging the deployment handpiece 430 away from thetissue generally in a direction parallel to the axis C-C since thedeployment device 422 is latched to the introducer 424. Alternately, thedeployment device 422 may be unlatched from the introducer 424 by urgingthe release buttons 500 inwardly toward the axis C-C to disengage thelatch tabs 504 from the latch openings 510 and urge the deploymentdevice 422 away from the introducer 424.

As illustrated and described herein the valve 280 (which may be commonlyreferred to as a duck bill valve) will permit medical devices to beinserted therethrough while restricting the flow of fluids therethrough.Either a biopsy device or a site marker deployment device, or both,could be latched to an introducer using a latch as described herein, asdesired. The latches described herein permit a medical device to bepositioned relative to an introducer hub in a desirable, confirmableposition for performing a treatment, such as removing tissue ordeploying a site marker or other treatment. An introducer hub, such asthe introducer hub 50, 250, 450 may be positioned relative to the tissueby an indicator on the introducer outer lumen 464, or a support gridaffixed to a MRI device. Additionally, the operation of the systems 20,220 are similar to the system 420, with variations in whether the biopsydevice or the deployment device (or both) are latched and unlatched fromthe introducer hub, as desired.

FIGS. 10-14 illustrate embodiments of the system 20 with adjustingmechanisms for accommodating cannula of differing lengths. That is,briefly, biopsy devices and marker deployment devices may be suppliedwith lengths of, for example, 10 centimeters (cm), 12 cm, or 14 cm.While introducers with lengths of 10, 12, and 14 cm may be supplied, auser may require a 12 cm introducer cannula for a biopsy device (such asthe dimension B2 of the biopsy device 22 of FIG. 6) and a 14 cmintroducer cannula for a site marker deployment device (such as thedimension B2 of the site marker deployment device of FIG. 9).

Since the introducer is generally not removed during the procedure ofremoving a biopsy device and deploying a marker for precision of markerpositioning, the user may attempt to insert the deployment devicepartially, estimate when the deployment device is 2 cm from fullinsertion into an introducer (where full insertion is shown FIG. 9), anddeploy the marker. This method may not provide the desired precision ofmarker positioning. Further, a user may stock multiple deploymentdevices having cannula of differing lengths to precisely deploy a markerdepending upon the cannula length of the biopsy device employed.

FIGS. 10-14 illustrate another embodiment of a spacer for a medicaldevice as a spacer 900. The spacer 900 includes an outer hub 902 and aninner hub 904. FIGS. 10 and 11 illustrate the spacer 900 coupled to anintroducer 906 and having a push rod 908 interposed therein, while FIGS.12 and 13 illustrate exploded views of the spacer 900.

The outer hub 902 includes a generally cylindrical outer surface 910, agenerally cylindrical inner surface 912, an outer hub proximal end 914,an outer hub distal end 916, and a locating finger 918 (FIGS. 11, 13,and 14) extending radially inward. The outer hub distal end 916 includesa generally cylindrical first latch surface 920 and a second latchsurface 922. In the embodiment illustrated, the outer hub distal end 916is similar to the hub distal end 844 of the spacer 830, in that aplurality of introducer hubs, such as the introducer hubs 50, 250, 450,650, 770, 824 may be releasably coupled thereto.

The inner hub 904 includes generally cylindrical outer surface 930, agenerally cylindrical inner surface 932, an inner hub proximal end 934,an inner hub distal end 936, an axial guide slot 938 (FIGS. 10, 12, 13and 14), a first circumferential locking slot 940, a secondcircumferential locking slot 942, and a third circumferential lockingslot 944. In the embodiment illustrated, the inner hub 904 also includesa plurality of first handles 950 and a plurality of second handles 952extending generally radially therefrom.

As best seen in FIG. 13, the axial guide slot 938, the firstcircumferential locking slot 940, the second circumferential lockingslot 942, and the third circumferential locking slot 944 do notintersect the inner surface 932. As best seen in FIGS. 11 and 14, theaxial guide slot 938, the first circumferential locking slot 940, thesecond circumferential locking slot 942, and the third circumferentiallocking slot 944 receive the locating finger 918. That is, the locatingfinger 918 is guided by the axial guide slot 938 as the inner hub 904moves axially relative to the outer hub 902, and the locating finger 918may be interposed within one of the first circumferential locking slot940, the second circumferential locking slot 942, and the thirdcircumferential locking slot 944. The locating finger 918 is interposedwithin one of the slots 940, 942, 944 as the inner hub 904 is rotatedrelative to the outer hub 902. When the locating finger 918 isinterposed within one of the first circumferential locking slot 940, thesecond circumferential locking slot 942, and the third circumferentiallocking slot 944, the inner hub 904 is restrained from moving axiallyrelative to the outer hub 902. In this manner, the spacer 900 canprovide a variable length between the outer hub distal end 916 and innerhub proximal end 934, as desired.

The spacer 900 may be provided with indications 960, 962, 964 (FIG. 10),to indicate which slot 940, 942, 944, the finger 918 is adjacent to, orlocked into. For example, the indication 960 may indicate a desiredposition for the end 914 of the outer hub 902 to be positioned when a 14cm introducer is coupled to the spacer 900, and the indication 964 mayindicate a desired position for the end 914 of the outer hub 902 to bepositioned when a 10 cm introducer is coupled to the spacer 900.

While the spacer 900 is illustrated with a push rod 908 interposedtherein, any medical device, such as a biopsy device 22, 222, deploymentdevice 422, or a biopsy device 528 may be inserted therein. The finger918 provides a first interference surface, the first circumferentiallocking slot 940 provides a second interference surface, the secondcircumferential locking slot 942 provides a third interference surface,and the third circumferential locking slot 944 provides a fourthinterference surface. In use, the first interference surface of thefinger 918 interferes with one of the second interference surface, thethird interference surface, or the second circumferential locking slot942 provides a fourth interference surface to restrain relative axialmovement between the inner hub 904 and the outer hub 902.

In addition to the deployment rod 432 (FIG. 9), the push rod 908 (FIGS.10 and 11) may be used as a target confirmation device, such as a styletor localizing obturater, for a cannula end, such as the distal end 60 ofcannula 52, the distal end 460 of cannula 452. That is, the end of atarget confirmation device, when positioned adjacent the distal end of acannula, will be visible under modalities such as a MRI, and will help auser to confirm where the end of the cannula is positioned relative to alesion when the device is inserted through the cannula. In other words,the use of target confirmation device with an imaging modality confirmsthat treatment, such as a marker, will be placed where it is intended.

The present invention has been particularly shown and described withreference to the foregoing embodiments, which are merely illustrative ofthe best modes for carrying out the invention. It should be understoodby those skilled in the art that various alternatives to the embodimentsof the invention described herein may be employed in practicing theinvention without departing from the spirit and scope of the inventionas defined in the following claims. It is intended that the followingclaims define the scope of the invention and that the method andapparatus within the scope of these claims and their equivalents becovered thereby. This description of the invention should be understoodto include all novel and non-obvious combinations of elements describedherein, and claims may be presented in this or a later application toany novel and non-obvious combination of these elements. Moreover, theforegoing embodiments are illustrative, and no single feature or elementis essential to all possible combinations that may be claimed in this ora later application.

1. (canceled)
 2. An introducer assembly for transcutaneously placing anelongate medical device in a patient, the assembly comprising: anintroducer including an introducer cannula having a proximal end and adistal end; and an axial distance adjustment system for providing anadjustable distance between a proximal end of the axial distanceadjustment system and the distal end of the introducer cannula, theaxial distance adjustment system comprising a first hub having a firstinterference surface, and a second hub having second and thirdinterference surfaces, wherein a distal end of the axial distanceadjustment system is releasably coupled to the proximal end of theintroducer, and wherein the first hub and the second hub are selectivelyrestrained from axial movement with respect to each other when the firstinterference surface contacts one of the second interference surface andthe third interference surface.
 3. The assembly of claim 2, wherein atleast one of the first hub and the second hub includes an axiallyextending surface portion and at least a portion of the firstinterference surface is selectively movable along the axially extendingsurface portion to thereby adjust the distance between the proximal endof the axial distance adjustment system and the distal end of theintroducer cannula.
 4. The assembly of claim 3, wherein the secondinterference surface and the third interference surface each projectsperpendicularly from the axially extending surface portion.
 5. Theassembly of claim 2, further comprising a plurality of indications toindicate a relative axial position of the first hub with respect to thesecond hub.
 6. The assembly of claim 5, wherein at least a portion ofthe plurality of indications indicates a length of the axial distanceadjustment system.
 7. The assembly of claim 2, wherein one of the firstand second hubs comprises a flange and the other of the first and secondhubs comprises a projection that cooperates with the flange to limitshortening of the distance between the proximal end of the axialdistance adjustment system and the distal end of the introducer cannula.8. The assembly of claim 2, the axial distance adjustment system furthercomprising a handle disposed at the proximal end thereof.
 9. Theassembly of claim 2, wherein the axial distance adjustment systemincludes a latch portion at a distal end thereof that releasably couplesthe distal end of the axial distance adjustment system to the proximalend of the introducer.
 10. The assembly of claim 2, wherein the firstand second hubs are disposed coaxially.
 11. The assembly of claim 10,wherein the introducer cannula and one of the first and second hubsdefine a continuous lumen.
 12. The assembly of claim 11, furthercomprising an elongate medical device slidably disposed in the lumen.13. The assembly of claim 12, wherein the proximal end of axial distanceadjustment system comprises a flange configured to cooperate with aprojection disposed on the medical device to limit distal insertion ofthe medical device through the lumen.
 14. The assembly of claim 12,wherein the elongate medical device is selected from the groupconsisting of a biopsy needle, a push rod, a stylet, and an obturator.15. The assembly of claim 2, wherein each of the first and second hubshas a cylindrical outer surface.
 16. The assembly of claim 2, whereinthe first interference surface is disposed on an orthogonal projectionfrom a surface of the first hub.
 17. The assembly of claim 16, whereineach of the second and third interference surfaces is disposed on acircumferential locking slot formed on a surface of the second hub. 18.The assembly of claim 17, wherein the second hub further comprises anaxial guide slot formed in the surface of the second hub, wherein theaxial guide slot is parallel to a longitudinal axis of the second hub.19. The assembly of claim 18, wherein each of the second and thirdinterference surfaces projects perpendicularly from the axial guideslot.
 20. An introducer assembly for transcutaneously placing anelongate medical device in a patient, the assembly comprising: anintroducer including an introducer cannula having a proximal end and adistal end; and an axial distance adjustment system for providing anadjustable distance between a proximal end of the axial distanceadjustment system and the distal end of the introducer cannula, theaxial distance adjustment system comprising a first hub having a firstinterference surface, and a second hub having second and thirdinterference surfaces, wherein the first and second hubs are disposedcoaxially, wherein a distal end of the axial distance adjustment systemis releasably coupled to the proximal end of the introducer, such thatthe introducer cannula and one of the first and second hubs define acontinuous lumen, and wherein at least one of the first hub and thesecond hub includes an axially extending surface portion and at least aportion of the first interference surface is selectively movable alongthe axially extending surface portion to thereby adjust the distancebetween the proximal end of the axial distance adjustment system and thedistal end of the introducer cannula.